My 2001 Prius with 134k miles has been running great but leaves a small amount of coolant on the ground after parking. I've had to add approximately 8 ounces per 100 miles. I had a mechanic friend look at it and he found where coolant was coming out at a point behind the drivers side headlight. He showed me where there are two hoses going into a junction. Our guess is that's the inverter coolant pump but just wanted confirmation. Additionally, I have read where people recommend removing the headlight and the left side of the bumper for easier access. Is this necessary or is it accessible without removing these things? Thanks! Notice the white arrow pointing to the leak location.
Lucious Garage has a YouTube video showing this removal. It is likely the pump of the hose /clamp on the inverter pump. Though you can see the pump if you look down the other way (on right of inverter instead in front between inverter and radiator).
Checked the hoses and clamps they're fine, leak coming from junction which evidently is the inverter pump?
Yes, so if you replace the inverter coolant pump you should be good. I don't know whether you can remove the Classic pump without first removing the bumper cover and headlight for access.
Toyota "improved" the inverter pump sometime in the last few years. If your car has over 100k miles and is still using the original pump, I recommend all Gen 1 owners change the pump as preventative maintenance measure...even if it is not leaking. After the Hybrid battery the next most common failures on Gen1's are tranny and/or inverter...parts which this pump helps keep cool. While I have no proof a new pump will add longevity to your tranny/invertor a new pump certainly won't make it worse and is way cheaper than a new tranny and/or inverter. The "new" pump has a silverish color mounting bracket. The original brackets were black. Part number G9020-47022 list price is $145 or so. You can change the inverter pump without removing the headlight if you lift the inverter out of the way and use a 1/4 inch drive 10mm swivel/wobbly socket...it's a bit of a PITA but it is do-able. It's easier to remove the left headlight but that requires lowering the bumper cover and getting to a couple fasteners hidden behind the fender liner. Don't forget to properly bleed the inverter anytime you breach the inverter/tranny cooling system. Then bleed it again after a couple days driving to make double sure you got all the air out.
Thank you! Now I'm really wondering about what it takes to replace it since it has this larger base. . . . Hummmm. Bob Wilson
I'm pretty sure the overall dimensions are the same as the factory pump...I didn't notice it any harder to install because of size. Once physical difference other than the silver bracket is a ridge at 12 and 6 o'clock on the hose fitting I'm pointing to in the photos below.
Thanks! I had bought a spare inverter pump several years ago but it came without the base ... just the plastic assembly. I had pulled parts off of a crashed NHW11 but it was a driver-side, front collision that pretty well destroyed the driver-side front. Your photos have given me a much better idea of what is involved. Bob Wilson
It is easiest to change the pump with bracket...While one of the bolts is hard to get to, it would be really really hard to swap the pump/rubber mount while leaving the bracket in the car...and then it would not be obvious to future mechanics the pump was changed since the bracket in the car would be old black style. Someone in a hurry could just yank out the old pump by the rubbers and let the new one floop around without being properly mounted via the rubber base, but that would be rather jenky.
You've given me an idea we need to discuss with the moderators: Create a series of 'never ending' surveys for each repairable part for the replacement time. It could be by year or miles, possibly both, but kept as a sticky. This becomes a way we start to model the likely failure modes of our NHW11 cars. Let me throw up an example, a 'test case' and lets see what it looks like and how it works. Bob Wilson
I'll add my thanks for the comparative pics. I'm faced with changing a stalled HV pump on my 2001 NHW11 (154k miles). I'd prefer to fit a new one, but not another of the original factory design, and these pics have clarified a previously confusing discussion on pump types/models over several threads.
